The error occurred on the remote node, but was reported here. It was also recorded on the remote node – do you know where it is recorded? What kind of monitoring would need to be in place to be proactively alerted by messages like this?

Now create the directory on the remote node and re-run the operation. This should succeed but it is still a poor configuration; we will investigate the reasons later in this lab.
SQL> host ssh collabn2 mkdir /u01/app/oradata
SQL> alter system set db_recovery_file_dest='/u01/app/oradata';
System altered.

Shutdown the database across the cluster. Then mount it on collabn1 and put the database into archivelog mode. No archivelog destination is assigned – where will the archivelogs go and why?